[251] "'Nibbāna to be seen for oneself, Nibbāna to be seen for oneself (sandiṭṭhikaṃ nibbānaṃ),' friend, it is said. In what way, friend, has Nibbāna to be seen for oneself been spoken of by the Blessed One?"
"Here, friend, a bhikkhu, quite secluded from sensual pleasures, … enters and dwells in the first jhāna. To this extent, friend, Nibbāna to be seen for oneself has been spoken of by the Blessed One in a provisional sense (pariyāyena). …
"Furthermore, friend, a bhikkhu, having completely transcended the base of neither-perception-nor-non-perception (nevasaññānāsaññāyatana), enters and dwells in the cessation of perception and feeling (saññāvedayitanirodha); and, having seen with wisdom, his taints (āsava) are utterly destroyed. To this extent, friend, Nibbāna to be seen for oneself has been spoken of by the Blessed One in the definitive sense (nippariyāyena)."
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.